<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

</body>

</html>
<script>
    function computed(str) {
        /*你的代码*/

        var str1 = str.replace('！','啊')
        newStr = str1.slice(0,1).toUpperCase()+str1.slice(1).toLowerCase()
        return newStr.split('').reverse().join("")
    }
    console.log(computed('hello world 我爱你！'));
</script>